The present invention is directed towards an Environmental Control System featuring contaminate neutralization means operating with an advanced semiclosed reverse Brayton air cycle loop with a unique air cycle machine. The air cycle machine includes dual turbines drivingly coupled to a compressor. Within the air cycle machine, one of the turbines is coupled to directly receive engine bleed air and extract useful work therefrom. The resulting Environmental Control system (ECS) minimizes the amount of bleed air required from the main engines, reducing the amount by up to 60 percent over present air cycle ECS's while providing integrated contaminate neutralization means within the ECS. The ECS and air cycle machine are described in greater detail in co-pending U.S. Pat. No. 4,967,565, issued Nov. 6, 1990, incorporated herein by reference.
Environmental Control Systems (ECS's) are in widespread use to provide a supply of conditioned air to an enclosed space, as for example an aircraft cabin and cockpit. Presently, the most efficient ECS's operate on a flow of bleed air taken from an intermediate or high pressure stage within a jet engine having multi-compression stages. The bleed air is first precooled within a primary heat exchanger, dumping heat to ram air, and is then ducted to a compressor. After compression, the air is routed through a series of heat exchangers and condensors, then expanded through a turbine before being ducted to the cabin. The turbine is mechanically linked and drives the compressor. These systems also incorporate various system specific bypass lines, valves and controller means to regulate the temperature of the air delivered to the cabin.